The television set of a cable television subscriber receives the program signals directly from the coaxial cable. With a view to cutting the cost of the coaxial cable and allowing more subscribers to receive the program signals on the same coaxial cable, the cable television operator makes use of a main line distributor on the primary line so as to distribute the program signals to a plurality of the secondary lines capable of reaching a number of cable television subscribers. In addition, the cable television operator must determine the extent of the loss of the transmission power of the coaxial cable in the course of transmission. Therefore, the main line distributor is provided additionally with a test hole for testing the magnitude of the power signal in order to determine if a power amplifier is called for. As shown in FIG. 1, a main line distributor 10 capable of branching out one primary line into three secondary lines is provided with a housing 11 having respectively at both front and rear ends thereof two connecting heads 12 for use in connecting the secondary lines of the subscribers with the primary line of the cable television antenna line transmission system. The housing 11 is further provided respectively in both left and right sides thereof with a test hole 14 having axially a test point, which is not shown in the drawing, for use as a reference in testing the magnitude of the power signal at the time when the subscriber's antenna is receiving the signal. The shortcomings inherent in the prior art power testing are described explicitly hereinafter.
The main line distributor 10 is generally fastened to a telephone pole or a rooftop. As a result, it is often inconvenient as well as hazardous for a technician to climb up to the main line distributor 10 to touch with a signal gauge the test point of the test hole 14 of the main line distributor 10. In addition, the test result is often inaccurate because the test is done hastily by the technician who is more concerned about his or her own safety.
The prior art power testing requires that the signal gauge is caused to make a direct contact with the test point of the test hole 14 of the main line distributor 10. Such a prior art testing method can often bring about an inaccurate power testing value in view of the fact that the direct contact between the signal gauge and the test point can result in an antagonism of impedance between the signal gauge and the coaxial cable.